Tooth Patch Research Articles

Performance Consequences of a Trophic Polymorphism: Feeding Behavior in Typical and Cannibal Phenotypes of Ambystoma tigrinum

Aquatic feeding behavior, prey capture performance, and morphological aspects of the feeding mechanism were compared in typical and cannibal phenotypes of Ambystoma tigrinum melanostictum to test the hypothesis that the trophic polymorphism affords a performance advantage in feeding. Similar-sized salamanders of the two phenotypes differed morphologically in size of the vomerine tooth patches and head width but not in size of the gape or mass of the hyoid retractor muscles used in suction feeding. Suction feeding and prey handling performance did not differ between the two morphs feeding on live guppies or small conspecific salamanders. However, differences were found in willingness to feed on conspecifics and prey handling performance when feeding on larger salamander larvae. Thus, cannibal morphs possess a significant performance advantage only during predation on large conspecifics. The performance advantage on large prey appears to be a consequence of greater prey handling ability facilitated by the increased size of the vomerine tooth patches.

The deepsea ophidiid fish genusLamprogrammus, a senior synonym ofBassobythites, with notes on the synonymy and distribution ofL. brunswigi

Bassobythites Brauer is a junior synonym ofLamprogrammus Alcock.L. macropterus Smith and Radcliffe is a junior synonym ofL. brunswigi Brauer.L. brunswigi is diagnosed by having: a basibranchial tooth patch; the postero-dorsal margin of the maxillary free or nearly so; a relatively well-developed opercular spine in larger examples. Known distribution is circumtropical except for the eastern Pacific, at trawled depths of 800–1600 m.

The dentition ofDiabolepis speratusChang and Yu, with further consideration of its relationships and the primitive dipnoan dentition

ABSTRACT The pterygoid plates and inner bones of the lower jaw of Diabolepis were further prepared and sections made of one dental plate to examine additional features of the dentition and to relate macrostructure to histology and growth. These observations confirm the position of Diabolepis within dipnoans. The growth pattern inferred from these observations is compatible with the general model for the growth of dipnoan tooth plates proposed by Smith (1988). New teeth are added from the anterolateral margin, the older posteromedial teeth are retained until worn flat, and the worn surface is repaired by new tissue forming as a blister superimposed on the old tissue. It is proposed that the dentition in Diabolepis is the most primitive for dipnoans. These primitive features include 1) paired dental plates consisting of radial rows of teeth that converge on the posteromedial corner, 2) radial tooth rows in which the teeth gradually increase in size from posteromedial to labial, 3) tooth patches of graded si...

A new deep-sea ophidiid fish,Bassozetus levistomatus, from the Izu-Bonin Trench, Japan

A new deep-sea ophidiid fish,Bassozetus levistomatus, is described on the basis of a single specimen trawled from the Izu-Bonin Trench, Japan, at a depth of 5,160 m. This species differs from its congeners by having the toothless head of its prevomer covered with the oral epithelium. It is further distinguished by the following combination of characters: no median basibranchial tooth patches, 29 pectoral fin rays, and 11 developed rakers on the first gill arch.

A New Species of Hemisilurus (Siluriformes, Siluridae) from the Mekong River, with Comments on Its Relationships and Historical Biogeography

Hemisilurus mekongensis n. sp. is described from the middle Mekong River basin. It differs from all other species of Hemisilurus in having fewer analand more pectoral-fin rays and a single vomerine tooth patch. Phylogenetic analysis shows that H. mekongensis and H. moolenburghi (from Borneo and Sumatra) are sister species that are distinguished from H. heterorhynchus (of which H. chaperi is a junior synonym) by a smaller eye, absence of pectoral-spine enlargement in males, and a longer maxillary barbel that in large females is distally expanded as a broad membrane that may separate into several fine filaments. Allopatric distributions of H. mekongensis and H. moolenburghi indicate a post-Pleistocene vicariance between drainages of mainland southeast Asia and the Indonesian islands. Sympatry among Hemisilurus species and Ceratoglanis, the sister group to Hemisilurus, indicates post-speciation dispersal between Sunda drainages during lowered Pleistocene sea levels.

Revision of the Indo-West pacific bathyal fish genusGlyptophidium (Ophidiiformes, Ophidiidae)

The ophidiid genusGlyptophidium is revised on the basis of 280 specimens. The seven recognized species fall into two well-defined species-groups: I.argenteum species-group withargenteum Alcock, 1889,effulgens sp. nov. andlucidum Smith et Radcliffe, 1913 is characterized i.a. by having 1 ray in each ventral fin, 1 median basibranchial tooth patch, 11 precaudal vertebrae, origin of dorsal fin above vertebrae nos. 3–4. II.macropus species-group withmacropus Alcock, 1894 (lectotype selected),longipes Norman, 1939,oceanium Smith et Radcliffe, 1913 andjaponicum Kamohara, 1936 (re-established and neotype described) is characterized i.a. by having 2 rays in each ventral fin, 2 median basibranchial tooth patches, 12–13 precaudal vertebrae, origin of dorsal fin above vertebra no. 1 or in front.

Taxonomy and distribution of ariid catfishes from the Arabian Gulf

Four morphologically distinct species of ariid catfish are found in northern regions of the Arabian Gulf, Arius thalassinus, A. dussumieri, A. tenuispinis and A. bilineatus, the latter having been frequently confused with and reported as A. thalassinus in earlier studies. An index of simple observations and measurements based on tooth patch structure and body dimensions was devised to distinguish between the four species. The recognition of A. tenuispinis and A. dussumieri in the Arabian Gulf greatly extends their reported distribution ranges.

Diagnostic Value of Morone Dentition

Abstract Widespread introductions of Morone species and hybrids have led to occasional difficulties in their identification. As the number of Morone morphotypes in individual water bodies continues to expand, or if introgression occurs, there will be an increasing need for diagnostic tools such as the dentition patterns described here. Two sets of specialized teeth are found in the soft tissue at the margins of the tongue–elongate tooth plates lateral to the basihyal and scattered teeth or tooth patches near the tip of the tongue. Variations among six species in these tooth formations, incorporated into a dental key, provide additional discriminatory information to supplement the oft-cited differences in dentition at the rear of the tongue. The presence of a single basihyal tooth patch as diagnostic for white bass Morone chrysops is not reliable as usually claimed because nearly all juvenile and many adult specimens examined bore two basihyal tooth patches. White perch Morone americana and yellow bass M. ...

Leptobrotula breviventralis, a New Bathyal Fish Genus and Species from the Indo-West Pacific (Ophidiiformes, Ophidiidae)

This new genus and species of Ophidiidae is described on the basis of four bathyally caught specimens, three from off the Hawaiian Islands and one from off Southeast Africa. It is characterized by a high, compressed body with a nonattenuate tail, an eye-diameter almost as long as the snout, a relatively strong opercular spine, short ventral fins, head of vomer enlarged with strong dentition and three basibranchial tooth patches, one median and a pair. Leptobrotula is closest to Glyptophidium with which it shares some advanced characters such as presence of paired basibranchial tooth patches, a large eye and head bones with thin crests. Leptobrotula differs from Glyptophidium in its compressed, high body, the non-attenuate tail, short ventral-fin rays and few, short pseudobranchial filaments (0-2).

Natural Hybrids of the Freshwater Sculpins Cottus bairdi and Cottus cognatus (Pisces: Cottidae): Electrophoretic and Morphometric Evidence

Natural hybrids of the sculpins Cottus bairdi and C. cognatus in the Sus- quehanna River drainage are electrophoretically identifiable on the basis of at least seven enzyme loci. Identification of Cottus hybrids on morphological grounds is, how- ever, somewhat speculative. Meristic characters overlap widely between the parental species, and hybrids generally do not possess intermediate character states. Hybrids can be tentatively identified on the basis of their intermediacy for two diagnostic characters which unambiguously distinguish the two species elsewhere in the Susque- hanna drainage: presence/absence of the palatine tooth patch, and number of pelvic fin rays. Principal component and discriminant analyses of suspected hybrids and samples of the parental species show the presumed hybrids to be somewhat intermedi- ate in morphology but to largely resemble C. cognatus in body form and meristic counts. Diagnostically intermediate specimens are more variable in their meristic and mensural characters than are nonintermediate individuals, and also display more bi- lateral asymmetry. F2 and backcross progeny were not detected in electrophoresis samples, but morphological evidence suggests that some introgression may be occur- ring.

Early development and buccal incubation in the fork-tailed catfish Arius graeffei Kner & Steindachner (Pisces : Ariidae) from the Clarence River, New South Wales

Fertilized oocytes of A. graeflei ranged from 12.3 to 15.2 mm in diameter (mean 13.3 mm). Eggs and larvae were incubated orally by the male; maximum observed brood size was 83. The branchial region of brooding males became distended to accommodate the eggs and larvae, and the oral epithelium thickened to cover the palatine tooth patches. The brooding period lasted from 6 to 8 weeks, with hatching at 4-5 weeks. Larvae began feeding on plankton soon after hatching, and juveniles were up to 59 mm total length when released. The average increase in weight from fertilization to release was 20%.

First record ofLepidion inosimae(Günther) andL. schmidtiSvetovidov (Pisces: Moridae) from New Zealand

Abstract Giant specimens of Lepidion collected in deep water east of New Zealand are referable to L. inosimae (Günther) and L. schmidti Svetovidov. Both species can be distinguished from L. microcephalus Cowper by the shape of the vomerine tooth patch and by differences in head length and orbit diameter.

Biochemical and Morphological Evolution of Hawaiian Bonefishes (Albula)

Biochemical and morphological evolution of Hawaiian bonefishes (Albula). Syst. Zool., 30:125–146.—Electrophoretic analysis of the protein products of 84 presumed gene loci for over 180 specimens reveals that two distinct species of bonefishes occur in Hawaiian waters. Both species are characterized by low levels of within-species variation (H = 0.005 and 0.022). However, the two species are well differentiated from each other; they possess fixed allelic differences at about 70% of the loci screened and have a calculated genetic distance of 1.16. There is no evidence that the two species hybridize although they co-occur on both a macro and a microgeographic scale. The magnitude of genetic differentiation between the two species suggests that they have been separate genetic units for approximately the last 20–30 million years. Although the two species of bonefishes in Hawaii are superficially very similar morphologically, there are a number of significant differences. The distributions of vertebral counts for the two species are completely non-overlapping, and the mean values for several meristic variables (including numbers of lateral-line scales, branchiostegal rays, and gill rakers) are significantly different in the two species. The single best field character for diagnosis is the shape of the lower jaw which is broadly rounded in one species and more angular and pointed in the other species. A number of traits associated with the head and feeding (lower jaw shape, number of gill rakers, shapes of tooth patches, and number of teeth) differ in the two species. Stepwise discriminant function analysis using 31 morphological characters demonstrates that the two species have distinctively different overall morphologies and that they can be distinguished with over 99% accuracy.

Meristic Characters of Two Morone Hybrids

Eight of 14 meristic characters counted for striped bass 9 (Morone saxatilis) x white bass d (M. chrysops) and striped bass 9 x white perch C (M. americana) hybrids showed statistical differences between the hybrid types. Of the eight, the clearest differentiating characters were: number of lateral line scales, number of scale rows above the lateral line, and number and appearance of tooth patches on the base of the tongue. Additionally, the dorsal fins were connected in the white perch hybrid. Both hybrids were generally intermediate between the parental species, but some traits resembled one parent more closely than the other. Frequency distributions for striped bass x white bass hybrid counts were skewed toward those characteristic of the white bass in four characters (second dorsal rays, pectoral rays, and scale rows above and below the lateral line) whereas counts of three characters (anal rays, tooth patches on the tongue and lateral line scales) were skewed toward those characteristic of the striped bass. Counts of five striped bass x white perch characters (pectoral rays, anal rays, scale rows above and below the lateral line, and tooth patches on the tongue) were skewed toward those characteristic of the striped bass, whereas counts of lateral line scales were skewed toward those of white perch. ,AND . 1972. Second discovery of mulDEPARTMENT OF BIOLOGY, SAMFORD UNIVERSItipl sex chro osomes among fishes. Experientia TY, BIRMINGHAM, ALABAMA 35209. Accepted

Aldrovandia oleosa, a New Species of the Halosauridae, with Observations on Several Other Species of the Family

Aldrovandia oleosa, a new halosaur closely related to A. phalacra (Vaillant), is described from the Tongue-of-the-Ocean, a deep oceanic trough in the Bahamas. Characters distinguishing A. oleosa from A. phalacra include the presence in the former of only 16-21 lateral-line scales anterior to the vent and an interspace between the pterygoid and palatine tooth patches that exceeds the length of the palatine patch. Unlike other halosaurs the new species has a very small gas bladder; however, its flesh is richly invested with oil. Fresh specimens of A. oleosa have a black head and a chocolate-brown body; preserved specimens become considerably faded. The new species is parasitized by a large copepod of the genus Lophoura. The parasite, which is highly specific for A. oleosa, attaches near the vent. A. oleosa is known from bathyal depths in the western Atlantic and the Gulf of Guinea region; it probably also occurs in the Indian Ocean.

The development and replacement of teeth in viviparous caecilians.

Tooth development and replacement in fetal and adult viviparous caecilians (Amphibia: Gymnophiona) are described and analyzed according to current theories of tooth succession. The fetal dentition differs from that of the adult in morphology, position, and function. Teeth are used by fetuses to scrape the oviducal epithelium, thus stimulating the secretion of a nutrient substance. Fetal dentitions vary in morphology and position in different species. The ontogeny of teeth of several species is described and the patterns of addition of loci and of replacement are analyzed. Loci are added both posteriorly along the jaw and between existing loci as the jaw grows prior to ossification; subsequently addition is restricted to the posterior part of the jaw. Tooth replacement is alternate. The several rows and patches of teeth are the result of retention of replacement series on the dentigerous elements. Tooth development and replacement in a series of juveniles and adults of different sizes in a single species are also considered. Post-fetal patterns of development and replacement are similar to those seen in larvae and adults of oviparous species. Variation in numbers of teeth and proportions of teeth at particular stages occurs ontogenetically and among individuals of the same size, though proportions occur in a similar pattern throughout the series. The general pattern of tooth replacement in fetuses and adults can be explained by either Edmund's Zahnreihen theory or by Osborn's Tooth Family theory, but replacement in fetal tooth patches and the fetal-adult dentitional transition are explained by neither.

The Insectivorous Genera Microgale and Nesogale (Madagascar)

The Insectivorous Genera <i>Microgale</i> and <i>Nesogale</i> (Madagascar)

A New Percoid Fish from Papua

BODY compressed, covered with cycloid scales of moderate size; lateral line complete, continuous, concurrent with the dorsal profile, each tube straight, not extending the whole length of the scale. Anterior profile scarcely notched above eyes. Mouth moderate, a little protractile, the gape not very oblique; maxillary exposed, without supplemental bone; jaws equal anteriorly. Several series of conical teeth in each jaw, those of the outer row somewhat enlarged; a patch of similar teeth on the vomer and a single row on each palatine; no teeth on the tongue. Cheek and operculum scaled.

II.—On the Dentition of the Palate in the South African Fossil Reptile Genus Cynognathus

The Cynodont reptilia from the Lower Karroo rocks of South Africa, characterized by relatively large incisors and relatively small, sharp-pointed, molar teeth, were grouped under the type genus Lycosaurus as Lycosauria. The removal of matrix from the palate of Ælurosaurus showed that in one member of the group at least the palate carries patches of teeth, each of which has the form of a small blunt flattened cone. From the fact that no Cynodont skull is available in which the mandible is free from the head, the nature of the palatal dentition is imperfectly known.

On Haloporphyrus lepidion (Risso)

I HAVE recently had occasion to examine two specimens of this rare and remarkable gadoid fish of the Mediterranean, originally described as Gadus lepidion by Risso (“Ichthyologie de Nice,” p. 118). The first was captured in my presence in the Gulf of Genoa, in July last, from a depth of about 900 metres, the second I received from Nice, where it was captured in deep waters on September 1 last, and I know of a third specimen taken at the latter place. All agree perfectly with Risso's description except in the general colour, a light brown, and not “un beau rouge incarnat”, while Risso appears to have overlooked the presence of a small patch of vomerine teeth. But our Mediterranean specimens present notable differences from that described by Dr. Gunther (“Catalogue of Fishes,” iv. p. 358), and referred by him to this species; besides being considerably larger, the British Museum specimen, which is from Madeira, has a much smaller eye and much longer snout and barbel. Such differences might depend on age, but I am strongly inclined to consider them specific, and therefore beg to draw the attention of ichthyologists to the case; should my opinion prove correct, the Madeiran fish might go by the name of Haloporphyrus guntheri.